Technical Abstract:
The predominant dietary form of vitamin K, phylloquinone, is present in certain plant oils. During hydrogenation of these plant oils, phylloquinone (K1) is converted to another form of vitamin K, dihydrophylloquinone (dK). The purpose of this study was to determine the K1 and dK content of fast foods and snack foods in the U.S. food supply. Representative samples of key foods (109 fast foods and 23 snack foods) obtained from the National Food and Nutrient Analysis Program, were analyzed for K1 and dK in duplicate by HPLC. Of the fast foods analyzed, including chicken products, hamburgers, burritos and nachos obtained from fast-food restaurants, the K1 and dK contents ranged from 0.4 - 23.7 and non-detectable (ND) - 69.1 µg/100g, respectively. Crackers and potato chips had wide ranges in K1 (1.4-24.3 µg/100g) and dK content (ND-102 µg/100g). When consumed frequently and in large amounts, fast foods and snack foods may be important contributors to vitamin K intake in the U.S. diet. However those fast foods and snack foods that contain high amounts of dK, may not have equivalent contribution to vitamin K status compared to foods containing high amounts of K1 due to differences in bioavailability.